There's no such thing as useless knowledge. You never know what doors it's going to open up for you.

I said Ted Cruz has been lying because if you say something that isn't true, and you say it over and over again, and you know that it's not true, there's no other word for it.

Why should we be letting people smoke their cigars in their comfortable chairs in Raqqa?

An important verity about knowledge is that the brain works most effectively with consciously retained information. We more easily remember what we want to recall later. When we feed our fourteen billion brain cells with information that will enrich us and help others, we are really learning to Think Big.

What is important - what I consider success - is that we make a contribution to our world.

You know, I'm a physician. I like to diagnose things. And, you know, I've diagnosed some pretty, pretty significant issues that I think a lot of people resonate with.

They were saying you would be a tremendous addition to the military, and we can get you into West Point with a full scholarship. And I simply said, I want to be a doctor. I really appreciate it.